US20060073623A1 - Methods of forming a microlens array over a substrate employing a cmp stop - Google Patents
Methods of forming a microlens array over a substrate employing a cmp stop Download PDFInfo
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- US20060073623A1 US20060073623A1 US10/956,789 US95678904A US2006073623A1 US 20060073623 A1 US20060073623 A1 US 20060073623A1 US 95678904 A US95678904 A US 95678904A US 2006073623 A1 US2006073623 A1 US 2006073623A1
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Images
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/31051—Planarisation of the insulating layers
- H01L21/31053—Planarisation of the insulating layers involving a dielectric removal step
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/311—Etching the insulating layers by chemical or physical means
- H01L21/31127—Etching organic layers
- H01L21/31133—Etching organic layers by chemical means
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14625—Optical elements or arrangements associated with the device
- H01L27/14627—Microlenses
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14683—Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof
- H01L27/14685—Process for coatings or optical elements
Definitions
- the present method relates to methods of forming microlens structures on a substrate.
- FIG. 1 is a cross sectional view of a microlens structure overlying a substrate.
- FIG. 2 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 3 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 4 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 5 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 6 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 7 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 8 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 9 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- FIG. 10 is a cross-sectional view of an intermediate microlens structure overlying a substrate.
- a method is provided to form a microlens to increase the light impinging on each pixel of an active photodetector device. If the microlens is fabricated properly to provide the proper shape and position, the microlens will direct light impinging on the lens onto the photodetector pixel. If the microlens has an area larger than the pixel area, it can collect light that would normally impinge on the areas outside each individual pixel and direct the light onto the photodetector pixel. Increasing the amount of light impinging on the photodetector pixel will correspondingly increase the electrical signal produced by the pixel.
- FIG. 1 shows an embodiment of a microlens structure formed according to an embodiment of the present method.
- a substrate 10 has at least one photo-element 12 formed thereon.
- the photo-elements 12 may be photosensitive elements, for example CCD camera pixels; or photosensors, or photoemissive elements.
- a transparent layer 14 has been deposited overlying the substrate 10 .
- Microlenses 20 are formed above a photo-element 12 . As shown, the top planar surface of the microlenses 20 corresponds to the top of a CMP stop layer 16 .
- An anti-reflection layer 22 is formed overlying the microlenses 20 .
- the microlens 20 is an approximately plano-convex lens with the convex surface directed towards the photo-element 12 .
- the thickness of the transparent layer 14 will be determined, in part, based on the desired lens curvature and focal length considerations. While having light impinge on the planar surface first, instead of the convex surface, increases known aberrations, this is less critical in the present application, which is concerned with increasing the amount of light impinging on each photo-element 12 , rather than trying to clearly focus an image.
- microlenses 20 are formed overlying the photo-elements 12 , eliminating the need to form the lenses and then transfer them to the substrate. Accordingly, a substrate having the desired photo-elements 12 formed on the substrate is prepared.
- FIG. 2 shows a substrate 10 having pixels 12 for sensing light.
- the transparent layer 14 has been deposited overlying the pixels.
- the CMP stop layer 16 has been deposited overlying the transparent layer 14 , followed by a lens-shaping layer 18 .
- the term “lens-shaping material”, or “lens-shaping layer” refers to a material layer that is suitable for isotropic etch processes to form the basic shape of a lens pattern, for example a lens-shaped cavity.
- FIG. 3 shows a layer of photoresist 24 deposited overlying the lens-shaping layer 18 . As shown, openings 26 have been patterned into the photoresist. The openings 26 will be used to introduce an etchant, and should be made as small as possible while still allowing introduction of the etchant.
- an isotropic wet etch is performed by introducing an etchant through the openings 26 to etch the lens-shaping layer 18 .
- the openings 26 are sufficiently small, they will act like a point source of etchant, producing a generally hemispherical etch pattern in the lens-shaping layer 18 .
- a variety of etchable materials may be used, for example polysilicon, amorphous silicon, silicon dioxide, or polyimide.
- a suitable etchant for isotropically etching the lens-shaping layer will need to be used, as understood by one of ordinary skill in the art.
- the lens-shaping layer 18 is silicon dioxide
- buffered HF may be used as the etchant.
- a mixture of nitric acid and hydrofluoric acid may be used if the lens-shaping layer 18 is amorphous silicon, or polysilicon.
- This etch step produces the initial lens shapes 28 as shown in FIG. 4 .
- the etch time may need to be limited to avoid lift-off of the photoresist 24 .
- the photoresist is then stripped, leaving the initial lens shapes 28 exposed as shown in FIG. 5 .
- a second isotropic wet etch increases the radius of the initial lens shapes to produce a final lens curvature, as shown in FIG. 6 .
- the overall thickness of the lens-shaping layer 18 will also be reduced during this second isotropic wet etch process, so the original thickness of lens-shaping layer 18 should be thick enough to account for the reduction caused by the second isotropic wet etch.
- the radius of curvature of adjacent lens shapes 32 increases, they may overlap. This is not an undesirable effect as it increases the density of the lens array, while desirably collecting as much light as possible. If the entire surface is covered with an array of lenses with no space in between, hopefully all light impinging on the surface of the lens array will be focused onto the underlying array of photo-elements 12 of the final device.
- an anisotropic etch for example a dry etch process is used to transfer the lens shapes through the CMP stop layer 16 and into the transparent layer 14 , as shown in FIG. 7 .
- the lens shape may be distorted during the transfer process, it should still be suitable for concentrating light onto the photo-elements 12 .
- This transfer process allows the lens shape to essentially be moved closer to the photo-elements 12 .
- the final distance between the bottom of the lens shape 32 and the photo-elements 12 will be determined in part by the focal length of the final lenses.
- a fluorine-based anisotropic etchant may be used, for example a fluorocarbon such as C 3 F 8 with argon.
- the ratio of C and F can be modified to change the etch profile.
- One of ordinary skill in the art will be familiar with a variety of anisotropic etch processes depending on the material selected for the lens-shaping material 18 , the CMP stop layer 16 and the transparent material 14 .
- a Cl 2 /BCl 3 etch may be used.
- a mixture of etchants may be used to control the etch rate through the different materials.
- an ion milling process may be used to achieve the anisotropic etch, without the need for special considerations related to etch chemistry.
- a lens material 40 is deposited to fill the lens shapes 32 .
- the lens material may be deposited by a sputtering process, a CVD process, a spin-on process, or other suitable process.
- a planarizing step is performed.
- a CMP process is used to planarize the lens material 40 .
- the CMP process continues until reaching the CMP stop 16 , as shown in FIG. 9 .
- the CMP stop layer 16 comprises a material with a lower polishing rate than lens-shaping material 18 or lens material 40 .
- the CMP stop layer may be composed of a metal such as Ir or Pt, a refractory metal such as Ti, TiN, Ni, Pd, Ta or other suitable refractory metal.
- a dielectric material such as silicon nitride, aluminum oxide or aluminum nitride may also be used.
- CMP stop layer 16 materials may also be used as lens-shaping materials 18 , but typically not in the same embodiment.
- the use of a CMP stop layer 16 may allow for greater control of the thickness of the final microlenses 20 and the lens to photo-element 12 distance.
- the amount of planarizing is not critical as long as enough lens remains to achieve improved light collection.
- the CMP stop layer may also block light between lenses reducing stray light.
- the AR layer 22 may be applied, producing the final structure.
- the substrate may be composed of any suitable material for forming or supporting a photo-element 12 .
- the substrate 10 is a silicon substrate, an SOI substrate, quartz substrate, or glass substrate.
- the transparent layer 14 will have a lower refractive index than microlenses 20 .
- the transparent layer 14 has a refractive index of approximately 1.5
- the microlenses 20 should have a refractive index equal to or greater than approximately 2.
- the transparent layer 14 is silicon dioxide or glass
- the microlenses 20 are composed of HfO 2 , TiO 2 , ZrO 2 , ZnO 2 , or other lens material with a refractive index of approximately 2 or higher.
- the AR layer is preferably composed of a material with a refractive index between that of air and the lens material.
- silicon dioxide may be used over microlenses having a refractive index of approximately 2.
- the thickness of the transparent layer 14 will be determined, in part, based on the desired lens curvature and focal length considerations, as well as the amount of etching caused by the second isotropic wet etch.
- the thickness of the lens-shaping layer used to initially form the lens shape will also be thick enough to accommodate the final curvature of the lens shape, but need not take into consideration the focal distance.
- the desired focal length of the microlenses 20 is between approximately 2 ⁇ m and 8 ⁇ m.
- the thickness of the transparent layer 14 as deposited should be thick enough to achieve the desired focal length distance following all etching and planarization steps.
- microlens structures are formed directly overlying the photo-elements 12 , there is no need to provide a separating layer, or to transfer the lens structure from a separate mold and reposition it.
Abstract
Description
- The present method relates to methods of forming microlens structures on a substrate.
- Increasing the resolution of image sensors requires decreasing pixel size. Decreasing pixel size reduces the photoactive area of each pixel, which can reduce the amount of light sensed by each pixel.
-
FIG. 1 is a cross sectional view of a microlens structure overlying a substrate. -
FIG. 2 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 3 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 4 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 5 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 6 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 7 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 8 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 9 is a cross-sectional view of an intermediate microlens structure overlying a substrate. -
FIG. 10 is a cross-sectional view of an intermediate microlens structure overlying a substrate. - Accordingly, a method is provided to form a microlens to increase the light impinging on each pixel of an active photodetector device. If the microlens is fabricated properly to provide the proper shape and position, the microlens will direct light impinging on the lens onto the photodetector pixel. If the microlens has an area larger than the pixel area, it can collect light that would normally impinge on the areas outside each individual pixel and direct the light onto the photodetector pixel. Increasing the amount of light impinging on the photodetector pixel will correspondingly increase the electrical signal produced by the pixel.
-
FIG. 1 shows an embodiment of a microlens structure formed according to an embodiment of the present method. Asubstrate 10 has at least one photo-element 12 formed thereon. The photo-elements 12 may be photosensitive elements, for example CCD camera pixels; or photosensors, or photoemissive elements. Atransparent layer 14 has been deposited overlying thesubstrate 10.Microlenses 20 are formed above a photo-element 12. As shown, the top planar surface of themicrolenses 20 corresponds to the top of aCMP stop layer 16. Ananti-reflection layer 22 is formed overlying themicrolenses 20. Themicrolens 20 is an approximately plano-convex lens with the convex surface directed towards the photo-element 12. The thickness of thetransparent layer 14 will be determined, in part, based on the desired lens curvature and focal length considerations. While having light impinge on the planar surface first, instead of the convex surface, increases known aberrations, this is less critical in the present application, which is concerned with increasing the amount of light impinging on each photo-element 12, rather than trying to clearly focus an image. - In one embodiment of the present process,
microlenses 20 are formed overlying the photo-elements 12, eliminating the need to form the lenses and then transfer them to the substrate. Accordingly, a substrate having the desired photo-elements 12 formed on the substrate is prepared.FIG. 2 shows asubstrate 10 havingpixels 12 for sensing light. Thetransparent layer 14 has been deposited overlying the pixels. TheCMP stop layer 16 has been deposited overlying thetransparent layer 14, followed by a lens-shapinglayer 18. The term “lens-shaping material”, or “lens-shaping layer” refers to a material layer that is suitable for isotropic etch processes to form the basic shape of a lens pattern, for example a lens-shaped cavity. -
FIG. 3 shows a layer ofphotoresist 24 deposited overlying the lens-shapinglayer 18. As shown,openings 26 have been patterned into the photoresist. Theopenings 26 will be used to introduce an etchant, and should be made as small as possible while still allowing introduction of the etchant. - Next an isotropic wet etch is performed by introducing an etchant through the
openings 26 to etch the lens-shapinglayer 18. If theopenings 26 are sufficiently small, they will act like a point source of etchant, producing a generally hemispherical etch pattern in the lens-shapinglayer 18. Since the lens-shapinglayer 18 does not need to be transparent, a variety of etchable materials may be used, for example polysilicon, amorphous silicon, silicon dioxide, or polyimide. A suitable etchant for isotropically etching the lens-shaping layer will need to be used, as understood by one of ordinary skill in the art. For example, if the lens-shapinglayer 18 is silicon dioxide, buffered HF may be used as the etchant. A mixture of nitric acid and hydrofluoric acid may be used if the lens-shapinglayer 18 is amorphous silicon, or polysilicon. This etch step produces theinitial lens shapes 28 as shown inFIG. 4 . The etch time may need to be limited to avoid lift-off of thephotoresist 24. - Once the
initial lens shapes 28 have been formed, the photoresist is then stripped, leaving theinitial lens shapes 28 exposed as shown inFIG. 5 . - A second isotropic wet etch, possibly using the same etchant as that used for the first isotropic wet etch, increases the radius of the initial lens shapes to produce a final lens curvature, as shown in
FIG. 6 . The overall thickness of the lens-shapinglayer 18 will also be reduced during this second isotropic wet etch process, so the original thickness of lens-shapinglayer 18 should be thick enough to account for the reduction caused by the second isotropic wet etch. As the radius of curvature ofadjacent lens shapes 32 increases, they may overlap. This is not an undesirable effect as it increases the density of the lens array, while desirably collecting as much light as possible. If the entire surface is covered with an array of lenses with no space in between, hopefully all light impinging on the surface of the lens array will be focused onto the underlying array of photo-elements 12 of the final device. - Following formation of
lens shapes 32, an anisotropic etch, for example a dry etch process is used to transfer the lens shapes through theCMP stop layer 16 and into thetransparent layer 14, as shown inFIG. 7 . Although the lens shape may be distorted during the transfer process, it should still be suitable for concentrating light onto the photo-elements 12. This transfer process allows the lens shape to essentially be moved closer to the photo-elements 12. The final distance between the bottom of thelens shape 32 and the photo-elements 12 will be determined in part by the focal length of the final lenses. If thetransparent layer 14 is silicon dioxide, a fluorine-based anisotropic etchant may be used, for example a fluorocarbon such as C3F8 with argon. The ratio of C and F can be modified to change the etch profile. One of ordinary skill in the art will be familiar with a variety of anisotropic etch processes depending on the material selected for the lens-shapingmaterial 18, theCMP stop layer 16 and thetransparent material 14. For example, a Cl2/BCl3 etch may be used. In some embodiments a mixture of etchants may be used to control the etch rate through the different materials. In another embodiment an ion milling process may used to achieve the anisotropic etch, without the need for special considerations related to etch chemistry. - As shown in
FIG. 8 , once thelens shape 32 is formed, and transferred to thetransparent layer 14, alens material 40 is deposited to fill thelens shapes 32. The lens material may be deposited by a sputtering process, a CVD process, a spin-on process, or other suitable process. - After the lens material is deposited, a planarizing step is performed. In an embodiment of the present method, a CMP process is used to planarize the
lens material 40. The CMP process continues until reaching theCMP stop 16, as shown inFIG. 9 . TheCMP stop layer 16 comprises a material with a lower polishing rate than lens-shapingmaterial 18 orlens material 40. The CMP stop layer may be composed of a metal such as Ir or Pt, a refractory metal such as Ti, TiN, Ni, Pd, Ta or other suitable refractory metal. In some embodiments a dielectric material such as silicon nitride, aluminum oxide or aluminum nitride may also be used. Some of the availableCMP stop layer 16 materials may also be used as lens-shapingmaterials 18, but typically not in the same embodiment. The use of aCMP stop layer 16 may allow for greater control of the thickness of thefinal microlenses 20 and the lens to photo-element 12 distance. In some embodiments, the amount of planarizing is not critical as long as enough lens remains to achieve improved light collection. In some embodiments, if metal is used for theCMP stop layer 18, the CMP stop layer may also block light between lenses reducing stray light. - Referring again to
FIG. 1 , after planarizing is achieved, theAR layer 22 may be applied, producing the final structure. The substrate may be composed of any suitable material for forming or supporting a photo-element 12. For example in some embodiments, thesubstrate 10 is a silicon substrate, an SOI substrate, quartz substrate, or glass substrate. - In an embodiment of the present microlens structure, wherein it is desirable to concentrate light onto the photo-
element 12, thetransparent layer 14 will have a lower refractive index thanmicrolenses 20. For example, if thetransparent layer 14 has a refractive index of approximately 1.5, themicrolenses 20 should have a refractive index equal to or greater than approximately 2. If thetransparent layer 14 is silicon dioxide or glass, themicrolenses 20 are composed of HfO2, TiO2, ZrO2, ZnO2, or other lens material with a refractive index of approximately 2 or higher. - In an embodiment of the present microlens structure comprising a single
material AR layer 22, the AR layer is preferably composed of a material with a refractive index between that of air and the lens material. For example, silicon dioxide may be used over microlenses having a refractive index of approximately 2. - The thickness of the
transparent layer 14 will be determined, in part, based on the desired lens curvature and focal length considerations, as well as the amount of etching caused by the second isotropic wet etch. The thickness of the lens-shaping layer used to initially form the lens shape will also be thick enough to accommodate the final curvature of the lens shape, but need not take into consideration the focal distance. In one embodiment of the present microlens structure, the desired focal length of themicrolenses 20 is between approximately 2 μm and 8 μm. The thickness of thetransparent layer 14 as deposited should be thick enough to achieve the desired focal length distance following all etching and planarization steps. - Note that since the microlens structures are formed directly overlying the photo-
elements 12, there is no need to provide a separating layer, or to transfer the lens structure from a separate mold and reposition it. - Although embodiments have been discussed above, the coverage is not limited to any specific embodiment. Rather, the claims shall determine the scope of the invention.
Claims (17)
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Application Number | Priority Date | Filing Date | Title |
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US10/956,789 US7029944B1 (en) | 2004-09-30 | 2004-09-30 | Methods of forming a microlens array over a substrate employing a CMP stop |
JP2005274720A JP4544466B2 (en) | 2004-09-30 | 2005-09-21 | Method for forming microlenses on a substrate using a CMP stop layer |
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US10/956,789 US7029944B1 (en) | 2004-09-30 | 2004-09-30 | Methods of forming a microlens array over a substrate employing a CMP stop |
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US20060073623A1 true US20060073623A1 (en) | 2006-04-06 |
US7029944B1 US7029944B1 (en) | 2006-04-18 |
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US10/956,789 Expired - Fee Related US7029944B1 (en) | 2004-09-30 | 2004-09-30 | Methods of forming a microlens array over a substrate employing a CMP stop |
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Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5324623A (en) * | 1991-06-04 | 1994-06-28 | Sony Corporation | Microlens forming method |
US5593913A (en) * | 1993-09-28 | 1997-01-14 | Sharp Kabushiki Kaisha | Method of manufacturing solid state imaging device having high sensitivity and exhibiting high degree of light utilization |
US5595930A (en) * | 1995-06-22 | 1997-01-21 | Lg Semicon Co., Ltd. | Method of manufacturing CCD image sensor by use of recesses |
US6104021A (en) * | 1997-04-09 | 2000-08-15 | Nec Corporation | Solid state image sensing element improved in sensitivity and production cost, process of fabrication thereof and solid state image sensing device using the same |
US6163407A (en) * | 1996-08-30 | 2000-12-19 | Sony Corporation | Microlens array and method of forming same and solid-state image pickup device and method of manufacturing same |
US6171885B1 (en) * | 1999-10-12 | 2001-01-09 | Taiwan Semiconductor Manufacturing Company | High efficiency color filter process for semiconductor array imaging devices |
US6379993B1 (en) * | 1997-04-07 | 2002-04-30 | Nec Corporation | Solid-state imaging device with a film of low hydrogen permeability and a method of manufacturing same |
US6423569B2 (en) * | 1997-09-26 | 2002-07-23 | Semiconductor Energy Laboratory Co., Ltd. | Photoelectric converter and fabrication method thereof |
US6437918B1 (en) * | 1996-07-22 | 2002-08-20 | Nippon Sheet Glass Co., Ltd. | Method of manufacturing flat plate microlens and flat plate microlens |
US20040080005A1 (en) * | 2002-10-25 | 2004-04-29 | Katsumi Yamamoto | Image sensor having combination color filter and concave-shaped micro-lenses |
US20040171184A1 (en) * | 2001-04-27 | 2004-09-02 | Semiconductor Energy Laboratory Co., Ltd. | Display device and manufacturing method thereof |
US6803250B1 (en) * | 2003-04-24 | 2004-10-12 | Taiwan Semiconductor Manufacturing Co., Ltd | Image sensor with complementary concave and convex lens layers and method for fabrication thereof |
US20040211884A1 (en) * | 2003-04-28 | 2004-10-28 | Ming Fang | Microlens integration |
US6872584B2 (en) * | 1999-09-21 | 2005-03-29 | Nec Electronics Corporation | Solid state image sensor and method for fabricating the same |
US6878564B2 (en) * | 2001-01-10 | 2005-04-12 | Silverbrook Research Pty Ltd | Method of manufacturing a light emitting semiconductor package |
US6940654B1 (en) * | 2004-03-09 | 2005-09-06 | Yin S. Tang | Lens array and method of making same |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3666918B2 (en) * | 1994-12-26 | 2005-06-29 | リコー光学株式会社 | Optical device / optical device manufacturing method |
US5824236A (en) * | 1996-03-11 | 1998-10-20 | Eastman Kodak Company | Method for forming inorganic lens array for solid state imager |
JP4521938B2 (en) * | 2000-06-19 | 2010-08-11 | キヤノン株式会社 | Imaging device |
-
2004
- 2004-09-30 US US10/956,789 patent/US7029944B1/en not_active Expired - Fee Related
-
2005
- 2005-09-21 JP JP2005274720A patent/JP4544466B2/en not_active Expired - Fee Related
Patent Citations (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5324623A (en) * | 1991-06-04 | 1994-06-28 | Sony Corporation | Microlens forming method |
US5593913A (en) * | 1993-09-28 | 1997-01-14 | Sharp Kabushiki Kaisha | Method of manufacturing solid state imaging device having high sensitivity and exhibiting high degree of light utilization |
US5595930A (en) * | 1995-06-22 | 1997-01-21 | Lg Semicon Co., Ltd. | Method of manufacturing CCD image sensor by use of recesses |
US6437918B1 (en) * | 1996-07-22 | 2002-08-20 | Nippon Sheet Glass Co., Ltd. | Method of manufacturing flat plate microlens and flat plate microlens |
US6163407A (en) * | 1996-08-30 | 2000-12-19 | Sony Corporation | Microlens array and method of forming same and solid-state image pickup device and method of manufacturing same |
US6379993B1 (en) * | 1997-04-07 | 2002-04-30 | Nec Corporation | Solid-state imaging device with a film of low hydrogen permeability and a method of manufacturing same |
US6104021A (en) * | 1997-04-09 | 2000-08-15 | Nec Corporation | Solid state image sensing element improved in sensitivity and production cost, process of fabrication thereof and solid state image sensing device using the same |
US6291811B1 (en) * | 1997-04-09 | 2001-09-18 | Nec Corporation | Solid state image sensing element improved in sensitivity and production cost, process of fabrication thereof and solid state image sensing device using the same |
US6423569B2 (en) * | 1997-09-26 | 2002-07-23 | Semiconductor Energy Laboratory Co., Ltd. | Photoelectric converter and fabrication method thereof |
US6803261B2 (en) * | 1997-09-26 | 2004-10-12 | Semiconductor Energy Laboratory Co., Ltd. | Photoelectric converter and fabrication method thereof |
US6872584B2 (en) * | 1999-09-21 | 2005-03-29 | Nec Electronics Corporation | Solid state image sensor and method for fabricating the same |
US6171885B1 (en) * | 1999-10-12 | 2001-01-09 | Taiwan Semiconductor Manufacturing Company | High efficiency color filter process for semiconductor array imaging devices |
US6878564B2 (en) * | 2001-01-10 | 2005-04-12 | Silverbrook Research Pty Ltd | Method of manufacturing a light emitting semiconductor package |
US20040171184A1 (en) * | 2001-04-27 | 2004-09-02 | Semiconductor Energy Laboratory Co., Ltd. | Display device and manufacturing method thereof |
US20040080005A1 (en) * | 2002-10-25 | 2004-04-29 | Katsumi Yamamoto | Image sensor having combination color filter and concave-shaped micro-lenses |
US6737719B1 (en) * | 2002-10-25 | 2004-05-18 | Omnivision International Holding Ltd | Image sensor having combination color filter and concave-shaped micro-lenses |
US6803250B1 (en) * | 2003-04-24 | 2004-10-12 | Taiwan Semiconductor Manufacturing Co., Ltd | Image sensor with complementary concave and convex lens layers and method for fabrication thereof |
US20040211884A1 (en) * | 2003-04-28 | 2004-10-28 | Ming Fang | Microlens integration |
US6940654B1 (en) * | 2004-03-09 | 2005-09-06 | Yin S. Tang | Lens array and method of making same |
Cited By (32)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8045252B2 (en) | 2004-02-03 | 2011-10-25 | Qualcomm Mems Technologies, Inc. | Spatial light modulator with integrated optical compensation structure |
US9019590B2 (en) | 2004-02-03 | 2015-04-28 | Qualcomm Mems Technologies, Inc. | Spatial light modulator with integrated optical compensation structure |
US8111445B2 (en) | 2004-02-03 | 2012-02-07 | Qualcomm Mems Technologies, Inc. | Spatial light modulator with integrated optical compensation structure |
US7535649B2 (en) | 2004-03-09 | 2009-05-19 | Tang Yin S | Motionless lens systems and methods |
US20050225877A1 (en) * | 2004-03-09 | 2005-10-13 | Tang Yin S | Motionless lens systems and methods |
US7944602B2 (en) | 2004-09-27 | 2011-05-17 | Qualcomm Mems Technologies, Inc. | Systems and methods using interferometric optical modulators and diffusers |
US7813026B2 (en) | 2004-09-27 | 2010-10-12 | Qualcomm Mems Technologies, Inc. | System and method of reducing color shift in a display |
US8344377B2 (en) | 2004-09-27 | 2013-01-01 | Qualcomm Mems Technologies, Inc. | Display element having filter material diffused in a substrate of the display element |
US20100165443A1 (en) * | 2004-09-27 | 2010-07-01 | Qualcomm Mems Technologies, Inc. | Systems and methods using interferometric optical modulators and diffusers |
US20090086301A1 (en) * | 2004-09-27 | 2009-04-02 | Idc, Llc | Display element having filter material diffused in a substrate of the display element |
US20060077514A1 (en) * | 2004-09-27 | 2006-04-13 | Sampsell Jeffrey B | System and method of reducing color shift in a display |
US7732246B2 (en) | 2004-12-29 | 2010-06-08 | Dongbu Electronics Co., Ltd. | Method for fabricating vertical CMOS image sensor |
US20060138531A1 (en) * | 2004-12-29 | 2006-06-29 | Lee Sang G | Method for fabricating vertical CMOS image sensor |
US20060138494A1 (en) * | 2004-12-29 | 2006-06-29 | Lee Chang E | Photodiode in CMOS image sensor and fabricating method thereof |
US7423307B2 (en) * | 2004-12-30 | 2008-09-09 | Dongbu Electronics Co., Ltd. | CMOS image sensor and method for fabricating the same |
US20080303073A1 (en) * | 2004-12-30 | 2008-12-11 | Sang Gi Lee | CMOS Image Sensor |
US8049257B2 (en) | 2004-12-30 | 2011-11-01 | Dongbu Electronics Co., Ltd. | CMOS image sensor |
US20060145224A1 (en) * | 2004-12-30 | 2006-07-06 | Lee Sang G | CMOS image sensor and method for fabricating the same |
EP1731928A3 (en) * | 2005-06-07 | 2006-12-20 | Yin S. Tang | Motionless lens systems and methods |
EP1731928A2 (en) * | 2005-06-07 | 2006-12-13 | Yin S. Tang | Motionless lens systems and methods |
US20070102842A1 (en) * | 2005-11-10 | 2007-05-10 | Irizo Naniwa | Process of microlens mold |
US20070194472A1 (en) * | 2006-02-17 | 2007-08-23 | Irizo Naniwa | Process of fabricating microlens mold |
US8872085B2 (en) | 2006-10-06 | 2014-10-28 | Qualcomm Mems Technologies, Inc. | Display device having front illuminator with turning features |
US9019183B2 (en) | 2006-10-06 | 2015-04-28 | Qualcomm Mems Technologies, Inc. | Optical loss structure integrated in an illumination apparatus |
US8304342B2 (en) | 2006-10-31 | 2012-11-06 | Texas Instruments Incorporated | Sacrificial CMP etch stop layer |
US20080102634A1 (en) * | 2006-10-31 | 2008-05-01 | Texas Instruments Incorporated | Sacrificial CMP etch stop layer |
US8798425B2 (en) | 2007-12-07 | 2014-08-05 | Qualcomm Mems Technologies, Inc. | Decoupled holographic film and diffuser |
US8848294B2 (en) | 2010-05-20 | 2014-09-30 | Qualcomm Mems Technologies, Inc. | Method and structure capable of changing color saturation |
US8670171B2 (en) | 2010-10-18 | 2014-03-11 | Qualcomm Mems Technologies, Inc. | Display having an embedded microlens array |
CN103219343A (en) * | 2012-01-23 | 2013-07-24 | 奥普蒂兹公司 | Multi-layer polymer lens and method of making same |
WO2021067357A1 (en) * | 2019-10-01 | 2021-04-08 | Hong Kong Beida Jade Bird Display Limited | Systems and fabrication methods for display panels with integrated micro-lens array |
US11782191B2 (en) * | 2019-10-01 | 2023-10-10 | Jade Bird Display (shanghai) Limited | Systems and fabrication methods for display panels with integrated micro-lens array |
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JP4544466B2 (en) | 2010-09-15 |
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